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Device files and directories must only be writable by users with a system account or as configured by the vendor.


Overview

Finding ID Version Rule ID IA Controls Severity
V-924 GEN002280 SV-63229r3_rule Medium
Description
System device files in writable directories could be modified, removed, or used by an unprivileged user to control system hardware.
STIG Date
Oracle Linux 5 Security Technical Implementation Guide 2020-02-25

Details

Check Text ( C-51941r3_chk )
Find all world-writable device files existing anywhere on the system.

Procedure:
# find / -perm -2 -a \( -type b -o -type c \) > devicelist

Check the permissions on the directories above subdirectories containing device files.

If any of the device files or their parent directories are world-writable, excepting device files specifically intended to be world-writable such as /dev/null, this is a finding.

These world-writable files on installation are intended to be world-writable:

/dev/full
/dev/null
/selinux/null
/dev/ptmx
/dev/random
/dev/tty
/dev/vsock
/dev/zero
/dev/log
Fix Text (F-53799r3_fix)
Remove the world-writable permission from the device file(s).

Procedure:

# chmod o-w

Document all changes.